Breakthrough in Modeling of Electrodiffusion Processes; Continuation and Extensions of the Classical Work of Richard Buck

Abstract

In 1978 Brumleve and Buck published an important paper [1] pertaining to numerical modeling of electrodiffusion. At the time their approach was not immediately recognized and followed. However, it has changed since the beginning of 21st century. The approach of Brumleve and Buck based on Nernst-Planck-Poisson (NPP) equations is utilized to model transient behavior of various electrochemical processes. Multi-layers and reactions allow extending applications to selectivity and low detection limit with time variability, influence of parameters (ion diffusivities, membrane thickness, permittivity, rate constants), and ion interference on ion-sensor responses. Solution of NPP inverse problem allows for optimizing sensor properties and measurement environment. Conditions under which experimentally measured selectivity coefficients are true (unbiased) and detection limit is optimized are demonstrated. Impedance spectra obtained directly from NPPs are presented. Modeling durability and diagnosis of reinforced concrete is presented. Chlorides transport in concrete is modeled using NPPs and compared to other solutions.